Since you are using stdio, a fifo might be a solution for your input. For example, open two terminals and do:
terminal 1: |terminal 2:
$ mkfifo fifo |
$ tail -f fifo | sed 's/a/A/' |$ echo hoppa > fifo
So, you could create a fifo in your ...
If you want it to keep a process running so you can use it then install the screen program then use screen at the start command in the cron job. This is where you use the /usr/bin/screen -d -m -fa -S Screen_Name_For_Instance /usr/bin/name_of_server_program to start it up. You can test the command at your command line. Once happy it runs correctly then the ...